We had the front tyres only replaced by a local tyre company on our Kia Sportage. Kia says the difference in tread between front and back has broken the four-wheel drive system and will cost £2k to repair. They say they see 10 cars a week with this issue. I can’t see anything in the car manual about it. How can they get away with not putting it in the manual? Shouldn’t tyre companies know and warn customers? I’m staggered.